Possible applications of pedicled vascularized bone transplants of the distal radius

Abstract

Reverse-flow pedicle vascularized bone grafts (VBGs) from the distal radius may be used for the surgical treatment of carpal fracture nonunions and avascular necrosis. Such grafts remain viable with quantifiable blood flow as demonstrated in a recent canine experiment. In this paper, the vascular anatomy of the distal radius is demonstrated and the surgical technique of VBG harvest is described. Our indications and results for treatment of scaphoid nonunion and Kienböck's disease are discussed and compared with the current literature. Fifteen patients with scaphoid nonunion and nine patients with Kienböck's disease stage IIIa were treated by reverse-flow pedicled VBG. Range of motion and grip strength were measured postoperatively and compared to the contralateral hand in all patients. An outcome questionnaire was used to measure patient's satisfaction and ADL's in the patients with Kienböck's disease. The radiologic diagnostic was performed with conventional X-rays, trispiral tomograms and MRI. In the scaphoid nonunion group, all patients were male, with an average age of 27.6 years. Five patients had prior attempts of autogenous bone grafting which failed. Six patients had a radiographic suggestion of proximal fragment avascular necrosis. All scaphoids healed. Time to union was 11.1 weeks on average. Average follow-up was 36.2 months. Pain relief, range of motion and grip strength were very promising. The treatment of Kienböck's disease was also promising in nine patients. Mean patient age was 31 years, and follow-up averaged 32 months. Six patients had complete pain relief, and three had occasional pain. Grip strength reached 86% of the contralateral side (a 25% improvement from preoperative values). Postoperative MRI demonstrated progressive revascularization with time. The results of treating scaphoid nonunions are promising. The use of vascularized bone graft facilitates rapid, reliable union of established scaphoid nonunion, even with proximal location and/or avascular changes. Clinical results in Kienböck's disease have been gratifying as well, with MRI evidence of gradual revascularization on follow-up studies.